INFO: task kworker/u4:0:8 blocked for more than 143 seconds. Not tainted 5.11.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:0 state:D stack:24248 pid: 8 ppid: 2 flags:0x00004000 Workqueue: tc_filter_workqueue tcindex_partial_destroy_work Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x999/0xe70 kernel/sched/core.c:5078 schedule+0x14b/0x200 kernel/sched/core.c:5157 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5216 __mutex_lock_common+0x124f/0x2f00 kernel/locking/mutex.c:1033 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 tcindex_partial_destroy_work+0x12/0x50 net/sched/cls_tcindex.c:287 process_one_work+0x789/0xfc0 kernel/workqueue.c:2275 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 INFO: task kworker/1:2:2990 blocked for more than 143 seconds. Not tainted 5.11.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:27480 pid: 2990 ppid: 2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x999/0xe70 kernel/sched/core.c:5078 schedule+0x14b/0x200 kernel/sched/core.c:5157 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5216 __mutex_lock_common+0x124f/0x2f00 kernel/locking/mutex.c:1033 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570 process_one_work+0x789/0xfc0 kernel/workqueue.c:2275 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Showing all locks held in the system: 3 locks held by kworker/u4:0/8: #0: ffff888016117138 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2248 #1: ffffc90000cd7d78 ((work_completion)(&(rwork)->work)){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2250 #2: ffffffff8d6eeb88 (rtnl_mutex){+.+.}-{3:3}, at: tcindex_partial_destroy_work+0x12/0x50 net/sched/cls_tcindex.c:287 1 lock held by khungtaskd/1648: #0: ffffffff8c711740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151 3 locks held by kworker/1:2/2990: #0: ffff8880226c1538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2248 #1: ffffc90001087d78 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2250 #2: ffffffff8d6eeb88 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570 1 lock held by in:imklog/8144: #0: ffff8880146eb270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:947 1 lock held by syz-executor422/8440: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1648 Comm: khungtaskd Not tainted 5.11.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x137/0x1be lib/dump_stack.c:120 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xce9/0xd30 kernel/hung_task.c:294 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4881 Comm: systemd-journal Not tainted 5.11.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lockdep_hardirqs_on_prepare+0x1/0x5e0 kernel/locking/lockdep.c:4051 Code: ff ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 4b ff ff ff e8 61 04 60 00 e9 41 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 RSP: 0018:ffffc90000faff20 EFLAGS: 00000093 RAX: ffffffff817dc7fc RBX: ffffffff89600068 RCX: ffff888013668000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff89600068 RBP: 0000000000000000 R08: ffffffff817dc7f3 R09: fffffbfff1b672e6 R10: fffffbfff1b672e6 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff888013668000 R15: ffffc90000faff58 FS: 00007f4a3ddbe8c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4a3b18f000 CR3: 0000000012b27000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __exit_to_user_mode kernel/entry/common.c:126 [inline] syscall_exit_to_user_mode+0x5a/0x180 kernel/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f4a3d0799c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffef4e2ad98 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: 0000000000000000 RBX: 00007ffef4e2ddc0 RCX: 00007f4a3d0799c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055dc28e3b9a3 RBP: 00007ffef4e2aee0 R08: 000055dc28e313e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055dc296b98a0 R15: 00007ffef4e2b3d0